Foam-fog applicators



April 29, 1958 G. F. HuRs'r FoAM-FoG APPLICAToRs 2 Sheets-Sheet 1 FiledApril 16. 1954 INVENTOR G'onooN F HuRs-r rNilmU ATTORNEYS April 29, 1958G. F. HuRs'r FoAu-Foc APPLICATORS 2 Sheets-Sheet 2 Filed April 16, 1954www www

BURUBUA nUnUnUn I I n n n n n i n n n n l n u l a l n u r l n 9 i NNN `Tma TR Nu WH m F. N 0 n m G United States arent hice FAM-FGG AFPLICATRSGordon F. Hurst, San dose, Application April 16, 1954, Serial No.423,674

9 Claims. (Cl. 169-45) This invention relates to lire ghting equipmentand more particularly to foam and fog applicators for producing andcontrolling the iiow of materials for extinguishing tires. Suchapplicators are commonly known as guns and will be so termed herein.

lt has been recognized for many years that a solid stream of water isnot only an inadequate rire extinguishing agent, but, in the case oftires involving volatile fluids, such as oil and gasoline, theapplication of a so-lid stream of water may spread the fire and increasefire damage.

Two agents have been developed which are particularly effective incontrolling such res and have been used extensively particularly inmilitary operations by the Navy and Air Force. The rst of these agentsis foam which is a stable cohesive blanket comprised of a mass of smallbubbles which effectively cools and smothers lires which are dicult tocontrol by other methods. Foam may be produced chemically ormechanically and it is with apparatus for the mechanical production andapplication of foam that the present invention is primarily concerned.

The second of these agents now used for combating fires which cannot becontrolled by solid water streams is fog which consists of a finelydispersed spray of water with or without fire extinguishing additives.While fog, under some circumstances, does not have the fireextinguishing eifectiveness of foam it is nevertheless preferred in manysituations because of the protection it affords the fire ghter byscreening him from the heat of a burning substance.

In many instances it is desirable that both kinds of equipment beavailable so that a selection of the type of equipment which may be usedwith best effect can be made instantly. Accordingly, in order to preventduplication of equipment so-called all-purpose guns have been developedby which either foam or fog may be delivered.

In the past such combined guns have been characterized yby relativelypoor performance as compared with the single purpose guns designedspecifically for either the delivery of fog or foam and are oftencumbersome, expensive and fail to produce foam effectively or fail toprovide adequate control of the quantity and pattern of the dischargedagent. Also many of the existing guns of this type require separatespray heads, adapters or other auxiliary equipment which must beinstalled or removed to permit conversion between fog and foam.

It is accordingly the major purpose and object of the present inventionto provide improved guns of the allpurpose type which are capable ofreadily selectively producing fog or foam.

It is a further object of the invention to provide improved combined fogand foam guns which may instantly and easily be converted from theproduction of foam to the delivery of fog and vice versa without theinstallation or removal of auxiliary units.

It is also an object of the invention to provide improved combined fogand foam guns having improved foam generating and shapingcharacteristics in which the foam is Patented Apr. 29, 1958 @i fullydeveloped in a primary chamber and is shaped and discharged in a desiredpattern in an enlarged secondary chamber.

lt is still another object of this invention to provide a combined foamfog gun with a rotatable valve body having parallel axially extendingpassages therethrough for selective seaied communication with a singleinlet passage in a stationary head or handle section and a novel sealconstruction therefor.

lt is an additional object to provide combined foam and fog guns havingseparate controls for regulatingthe quantity and pattern of thedischarged agents, each set of controis being operable independently ofand without affecting the other controls.

it is a further object to provide improved foam and fog guns which areof simple, durable, lightweight and inexpensive construction.

Further objects and advantages will become apparent as the descriptionproceeds in connection with the accompanying drawings in which:

Figure 1 is a partial longitudinal section of a preferred embodiment ofthe present invention;

Figure lA is a continuation of Figure l;

Figure 2 is an elevation of the discharge of Figures l and lA;

Figure 3 is a transverse section taken along line 3-3 of Figure l;

Figure 4 illustrates partly longitudinal section a modified invention;

Figure 5 is an enlarged fragmentary section of a portion of the gun ofFigure 4; and

Figure 6 is a fragmentary sectional view showing a end of the gun inelevation and partly in embodiment of the present further modificationof the invention.

Referring now more particularly to Figures 1 and lA of the drawings, theprincipal elements of the gun thereshown are the handle assemblyindicated generally at 20, the selector valve body assembly 22, theaspirating cage assembly 2li, the primary foam generating chamberassembly 2o, the secondary foam shaping chamber and foam nozzle assembly2d, the fog tube assembly 30 and the fog nozzle assembly 32.

The handle 2t) is of one piece construction and made of brass or similarmaterial which is corrosion resistant and capable of withstanding thenormal operating pressures. The grip portion 3o of the handle is hollowand at its lower end is provided with a threaded terminal portion 313 inwhich a sleeve extension 4t) is secured. The outer end of extension 4dis adapted to receive a standard sealed swivel hose connection assembly42 connected to a high pressure flexible lhose d4 and including a.filter screen 46 which extends through the extension 40 into the lowerend of the hollow grip 36. In operation the hose 44 is connected to asolution of water and a commercially available foam stabilizer which, asis well known in the art, is a substance for increasing the surfacetension of the water, or to a source of water under pressure and isadapted through use of any suitable and well known pick-up tubestructure to selectively aspirato a foam stabilizer into the waterstream. Ordinarily the solution or water stream will be supplied at apressure in the neighborhood of 8O to 600 p. s. i.

At its upper end, `the hollow grip 36 communicates through a passage Silwith an enlarged valve inlet passage 52 in which a sealing O-ring 54 andan annular valve seat member 56 are positioned, the latter preferablybeing constructed of reinforced nylon or like iiibrous material.

The valve seat member 56 is provided on its outer end witha thin sealingedge which is adapted to selectively sealingly contact the area of theend face of valve body 22 surrounding either aperture 60 are aperture 62formed in the selector valve body 22 which is rotatably mounted on ballbearings 64 received in suitable grooves formed in the interior of asubstantially cylindrical integral extension 66 of the handle 20 Thebearings 64 also extend into grooves formed in the outer surface of theselector valve body 22 and thus function as thrust bearings preventingseparation of the selector valve body 22 and the handle under allpressure conditions. The bearings 64 may be removed through openingsprovided in the grip which are normally closed by set screws 70. Theconnection between the grip 20 and the selector valve body 22 iscompleted by a sealing O-ring 7?. which prevents the escape of lluid tothe bearings 64 or to the exterior of the selector valve body.

The passage 60 communicates with an enlarged cham ber 74 in valve body22 in the outer wall 76 of which a plurality, preferably eight, spraynozzles 78 of conventional construction well known in the foam art arethreadedly mounted. By appropriate change in the size of nozzles 78, the4capacity of the gun may be varied from 20 to 50 gallons per minute.

The passage 62 is in turn connected through an internal centrallylocated passageway '79 to a boss 80 formed centrally of the selectorvalve body 22 into which is threaded a tube 82 which forms the initialportion of the fog tube assembly 30. The tube 82 extends through acentral aperture in the wall 76 and is surrounded by sealing O-ring 84mounted in the wall.

From the foregoing it will be apparent that with the selector valve body22 positioned as shown in Figure l, iluid will be delivered from thehose 44 through the hollow grip 36, through the passage 60 to thechamber 74 for delivery through the'spray nozzles 78 to the aspiratingcage assembly 24. However, if the selector valve body 22 is rotated 180from the position shown in Figure l, the aperture 62 will be put intoregistry with the aperture 50, ilow through aperture 60 will be cut offand established through aperture 62 and passage 79 to the interior ofthe tube 82 for delivery to the fog tube assembly 30. To facilitaterotation of the selector valve 22 an operating handle 86 is mounted in aside wall thereof. To retain the selector valve body 22 in either of itsadjusted positions a trigger type latch 90 is pivoted as at 92 on thegrip assembly and is urged by a spring 94 into contact with bifurcatedupper and lower abutments 96 and 98 on the selector valve body. It willbe appreciated that other conventional detent structures may be used inplace of the trigger 90.

The aspirating cage 24, which is preferably an aluminum alloy casting,is threaded onto the selector valve body 22 at 100 and is provided witha convergent wall portion 102 leading to a throat portion 104. Theenlarged portion of the aspirating cage 24 has `a plurality, preferablyfour, circumferentially spaced air inlet openings 106 formed rearwardlyof the outlet openings of the spray nozzles 78. It will be noted thatthe junction between the convergent wall portion 102 and the throatportion 104 of the aspirating cage is positioned slightly forwardly ofthe spray nozzles 78. `This arrangement, coupled with the location ofthe air inlets 106, permits the etiicient entrainment oflarge quantitiesof air in the spray discharge from nozzles 78 and precludes thepossibility of the emission of foam through the passages 106 due to theresidual orback pressure normally developed in forcing the foam throughthe gun. The mixture of water, foaming agent and air passes through theaspirating cage 24 into a primary foam generating tube 108 preferablyformed of thin sheet aluminum which extends into the aspirating cage 24and is secured thereto as by screws 110. The foam tube 108 thus formswith the fog tube assembly 30, an elongated primary foam generatingchamber 111. Y

At its outlet end the tube 108 communicates with a secondary foamshaping chamber 112 formed between the fog tube assembly 30 and anenlarged foam discharge outer nozzle member 114 which is preferably analuminum alloy casting. The nozzle member 114 which is provided with anannular inwardly extending flow control lip 115 is rotatably andslidably mounted on the tube 108 by a reduced portion 116 which carriesa spaced pair of sealing O-rings 118.

A nozzle control ring 120 is secured to the tube 108 as by screws 122and is provided with a threaded portion 123 which engages a matinglythreaded portion 124 of the nozzle member 114 so that rotation of thelatter will effect its axial displacement with respect to the former andtube Rearward movement of the nozzle member 114 is limited bycooperating abutment shoulders 126 and 128 formed on control ring 120and nozzle member 114, respectively, and forward movement of the nozzlemember 114 is limited by a stop member 130 secured to the outer end ofthe tube 108 by screws 132 for mating cooperation with the inner wall oftransition section 134 connecting nozzle member 114 and reduced portion116 of foam nozzle assembly 28.

The foam nozzle is completed by a torpedo 134 mounted on the outer endof the main fog tube 136 the other end of which is secured through an`adapter 138 to the tube 82.

To facilitate handling and to protect the gun, the central exposedportion of foam generating tube 108 and portion 116 of the nozzle member114 are wrapped with lengths of braided cotton cording A140 and 142 anda protective neoprene bumper 144 is provided on the outer exposed end ofthe nozzle member 114. A synthetic rubber cover may be used, if desired,in place of the cording.

The quantity and pattern of the fog is controlled by the inner nozzleassembly 32 which comprises a female fog stream nozzle member threadedinto the foam torpedo 134 and having a central fluid passage 152and amale control assembly or torpedo 154. An O-ring seal 151 seals member150 and torpedo 134 against leakage therebetween. The torpedo assembly154 comprises a .valve element 156 integrally secured to a positioningmember comprising four vanesf158, the outer edges of which are adaptedto be received with a sliding fit within the main fog tube 136. Thetorpedo assembly 154 is mounted on one end of a control rod 160 whichextends along the length of the gun and is slidably received in alignedbores 162 and 164 in the selector valve body 22 and handle assembly 20respectively. The bores 162 and 164 are sealed by O-n'ngs 166 and 168,respectively.

The outer end of control rod 160 is attached by nuts to a collar 172secured by edge peening as at 174 to a knurled control knob threadedlymounted on a stud sleeve 176 which encircles control rod 160 and isthreaded into the grip .assembly 20. Stud sleeve 176 is held in place bya set screw 178. Accordingly, rotation of control knob 175 will displacethe valve member 156 axially with respect to the seat assembly 150 topermit desiredcontrol of the quantity and pattern of the discharged fogstream.

In operation, assuming the gun to be supplied with a suitable solutionof water and foaming agent under pressure and the valve selector body 22to be in the position shown in Figure l, the solution is delivered bythe jets 78 in a number of nely dispersed streams to the aspirating cage24. The ow of fluid through the spray jets 78 entrains large quantitiesof air which enter through the large apertures 106 in the aspiratingcage and the turbulence in the aspirating cage causes the solution tomix with the entrained air to form foam. The formation of foam continuesas the liquid-air mixture passes through the foam generating chamber 111formed by tube 108 and final development of a cohesive fine bubble foamoccurs in the tube 108 before the mixture reaches the secondary chamber112 formed about the outlet of the tube 108. The secondary chamber 112is thus utilized essentially only for shaping the foam and dischargingit in the desired pattern. With nozzle member 114 in the position shownthe foam will issue in a dispersed spray pattern. This pattern mayreadily be changed as desired by advancing nozzle member 114 to theright as viewed in Figure 1A, such movement of the nozzle beingelfective to gradually eliminate the divergent effect of the cone andfinally convert the spray pattern into a solid axially discharged foamstream. 1t is to be noted that since the foam generation and shaping areeiected independently the variation in the discharge pattern of the foamis effected without reducing the quantity of foam discharged so thatregardless of the discharge pattern employed the foam will always bedischarged at the predetermined maximum rate.

If conditions require, the gun can instantly be converted to deliver awater fog or stream by releasing the latch 90 and rotating the selectorvalve assembly 22 by the handle 86 to bring passage 62 into registrywith passage 50. The introduction of foam stabilizer into the liquidsupplied to the gun need not be discontinued since negligible quantitiesof foam will be produced. All of the uid will thus be delivered to thefog tube assembly 30 and will issue from the nozzle 150 when the valve156 is opened by rotation of the control knob 175. An effective lireextinguishing agent is formed which screens the operator from theintense heat of the tire. Variation in both the discharge pattern andquantity of fluid discharged can be eifected by appropriate adjustmentof the valve 156.

Basically the modified gun illustrated in Figures 4 and 5 is the same asthe gun above described and is convertible for the production of eitherfog or foam and controllable in exactly the same manner as the gun ofFigures 1 and 1A. However it will be seen from a comparison of Figures 1and 1A and Figure 4, which are drawn to the same scale, that the primaryfoam generating chamber 190 and the secondary foam shaping charnber 192of the gun of Figure 4 are considerably shorter than the correspondingchambers of the gun of Figures 1 and 1A. The shortening of the overalllength of the gun is made possible by the use of the screen assemblyindicated generally at 200 which accelerates the formation of foam andthus renders a chamber of the length of that shown in Figures l and 1Aunnecessary. The aspirating cage 202 and the control ring 204, aregenerally similar to the corresponding elements 24 and 120 of the gun ofFigures l and lA but are modified to receive the screen assembly 200. Tothis end, the aspirating cage 202 is provided with an enlarged bore 206in which the screen assembly 200 is held by an annular extension 20S ofthe 4control ring 204. The aspirating cage 202 and the control ring 204are provided with mating flanges 210 and 212 respectively which aresecured together by screws 214. The screen assembly 200 preferablycomprises three annular screen sections 216 separated at theirperipheries by washers 218. The foam tube 220, which is secured to thecontrol ring 204 by a plurality of screws 222, extends from the screenassembly 200 into the secondary foam generation chamber 192 where itterminates in a flared section 226 which functions as a stop forlimiting forward movement of the outer nozzle member 22S. Except forchanges in dimensions, the latter is generally similar to the nozzlemember 114 described in detail above. The protective cotton cording 230and the protective bumper 232 are similar to the corresponding elementsdescribed in connection with Figure 1A.

The two forms of the invention are generally interchangeable, the gun ofFigures l and 1A being preferred in circumstances where it is necessaryto project the foam stream as far as possible and the gun of Figures 4and 5 being preferred under circumstances where size and weight are ofcontrolling importance.

Both guns are characterized by simplicity, reliability, versatility andimproved control characteristics and both may be converted from foam tofog or vice versa by relatively simple adjustments which may be madeinstantly and do not require the addition or deletion of auxiliary partssuch as separate spray heads, nozzles or adapters generally necessary inprior constructions.

If desired, either of the basic guns may be equipped with the attachmentshown in Figure 6 for producing a flat fog pattern. With furtherreference to Figure 6, the attachment as at 236 to the projection 238formed on a ring 240 clamped between the fog nozzle and the foam torpedo134.

In the position shown, the deector plate 234, which projects angularlyacross the fog stream discharged through the opening 152, will form thefog into a fiat pattern. When the usual fog pattern is desired the plate234 may be swung back out of registry with the opening 152. By rotationof the ring 240 with the plate 234 in the position shown the directionof the flat fog stream may be varied as desired.

The invention may be embodied in other speciiic forms without departingfrom the spirit or essential characteristics thereof. The presentembodiments are therefore to be considered in all respects asillustrative and not restrictive, the scope of the invention. beingindicated by the appended claims rather than by the foregoingdescription, and all changes which come within the meaning and range ofequivalency of the claims are therefore intended to be embraced therein.

What is claimed and desired to be secured by United States LettersPatent is:

1. A combined foam-fog gun or applicator comprising a hollow hand gripportion providing a liquid inlet and a liquid outlet terminating in anopen ended chamber; valve means rotatably mounted in said chamber andhaving one end `wall providing a. pair of spaced ports adapted forselective communication with said outlet and respectively leading to anannular chamber in said valve means and a centrally located coaxialpassage and also having an opposed end wall; passage means communicatingwith said centrally located coaxial passage and extending axiallytherefrom to form a fog discharge nozzle; a plurality of spaced sprayjets extending through said opposed end wall into communication withsaid annular chamber; an annular passage surrounding said passage meansand said spray jets and extending from said opposed end wall of saidvalve means to form a foam discharge nozzle and having a plurality ofair admission ports adjacent said spray jets; means for supplying anaqueous liquid to said inlet; and means for rotating said valve means toselectively connect one or the other of said ports to said outlet tosupply liquid to said spray jets whereby liquid sprayed therefrom willaspirato and entrain air into said sprayed liquid to produce foam insaid annular passage and discharge it .from said foam nozzle oralternately supply liquid to said centrally located coaxial passage andsaid fog nozzle to thereby produce a fog spray.

2. The gun or applicator of claim l wherein said liquid outlet receivesa fibrous cylindrical seat having an end protruding therefrom intosealing engagement with said one end Wall and of a diameter to encirclethe selected one of said ports.

3. The gun or applicator of claim 1 wherein said foam nozzle surroundssaid fog nozzle and is mounted for move ment with respect thereto tovary the pattern of said discharged foam between a widely divergentspray and a forwardly directed stream.

4. The gun or applicator of claim 3 wherein said annular passage isformed by a primary foam forming tube section carried by said valvemeans and having forwardly inclined air admission ports disposedrearwardly of said jets and an additional tube section mounted formovement axially of said primary foam forming tube section and having asecondary foam forming chamber of substantially greater cross-sectionalarea than said primary form forming tube section terminating insurrounding relation to said fog nozzle to form an annular foamdischarge passage.

5. The gun or applicator of claim 4 wherein the exterior of said fognozzle is of progressively increasing diameter from a point asubstantial distance inwardly from said terminus of said additional tubesection in its retracted position to a point just inwardly from saidterminus in said retracted position and forms a flow dividing torpedo4for imparting a divergent trajectory to foam discharged through saidannular passage in the fully retracted position of said additional tubesection and positions nearest said fully retracted position.

6. A foam and fog gun comprising means forming an elongated foamgenerating chamber having air inlet openings at one end, a plurality ofspray nozzles adjacent said openings, means defining a restrictedorifice at the end of said passage adjacent said foam discharge orifice,and means for selectively introducing fluid into said charn- `berthrough said nozzles or into the end of said passage remote from saidrestricted orifice.

7. A foam and fog gun comprising, a first tubular member having a fluidinlet at one end and a fog discharge nozzle at the other end, a secondtubular member surrounding said first tubular member in concentricrelation therewith, the outer surface of said first tubular member inthe inner surface of said second tubular member forming a foamgenerating chamber, a plurality of spray devices opening into one end ofsaid foam generating chamber in surrounding relation with said firsttubular member, means defining a plurality of air inlets in said secondtubular member adjacent said nozzles, means forming cooperating surfaceson the adjacent ends of said tubular members to control the discharge offoam from said chamber, and means for selectively connecting saidnozzles and said fluid inlet at said one end of said first tubularmember to a source of fluid under pressure.

8. In a foam and fog gun, a first tubular member forming an elongatedprimary foam generating chamber, means forming a plurality ofcircumferentially spaced air inlets in the Wall of said chamber adjacentone end thereof, a plurality of spray devices adapted to introduce adispersed mixture of water and foaming agent into said one end of saidprimary foam generating chamber, a second tubular member having aportion mounted on said first tubular member `for movement axiallythereof, said second tubular member also having an enlarged portionforming an enlarged secondary foam generating chamber surrounding theOpposite end of said primary foam generating chamber, and fixed nozzlestructure within the outer discharge end of said second tubular memberhaving flow directing surfaces inclined with respect to the axes of saidprimary and secondary'foam generating chamber whereby upon axialmovement of said second tubular member the configuration of said outletmaybe changed to vary the foam discharge pattern.

9. The gun of claim 8 togetherwith a screen assembly for acceleratingthe generation of foam, said assembly being mounted in and extendingtransversely of said primary foam generating chamber.

References Cited in the file of this patent UNITED STATES PATENTS

